Highly integrated dynamic semiconductor memories store information as a charge on a capacitor. This basic principle has been described in U.S. Pat. No. 3,387,286. Since then, this solution has been modified several times; however, the intrinsic features of this principle can still be found in all manufactured dynamic semiconductor memory cells as a basic component of highly integrated dynamic semiconductor memories. The adavantage of such memory cells is based upon the small required space and the need for only one field effect transistor to realize the memory cell.
A further reduction of the size of the memory cell, required by ever increasing integration, results necessarily in a reduction of the stored charge. Highly sensitive sensor amplifiers are required in order to read this reduced charge; at the same time more time is needed to read the memory cell; in so far as reading may be at all still possible.
In addition, the relative sensitivity to distrubances is increased, for instance to .alpha. radiation.